"""Load saved logs for offline analysis.

Accepts both raw serial captures and this tool's session logs, whose lines
look like "[14:02:11.532] I (1234) TAG: msg" and whose host events look
like "[14:02:11.532] --- reset issued by tool ---".
"""

from __future__ import annotations

import re
from pathlib import Path

from .logline import LineKind, LogLine, parse_line, split_glued

_SESSION_PREFIX = re.compile(r"^\[(\d\d):(\d\d):(\d\d)\.(\d{3})\] ")
_HOST_EVENT = re.compile(r"^--- .* ---$")


def read_log_file(path: Path) -> list[LogLine]:
    text = path.read_bytes().decode("utf-8", errors="replace")
    out: list[LogLine] = []
    for i, raw in enumerate(text.splitlines()):
        host_time = i * 0.001  # raw capture: keep order, no wall clock
        if m := _SESSION_PREFIX.match(raw):
            h, mi, s, ms = (int(g) for g in m.groups())
            host_time = h * 3600 + mi * 60 + s + ms / 1000
            raw = raw[m.end():]
            if _HOST_EVENT.match(raw):
                out.append(LogLine(raw, LineKind.HOST, host_time))
                continue
        out.extend(parse_line(part, host_time) for part in split_glued(raw))
    return out